Recruiting

Dopaminergic Treatment

Sponsor:

University of Texas Southwestern Medical Center

Code:

NCT06489483

Conditions

Parkinson Disease

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Accepted

Interventions

Action Regulation Movement Task

Study Details

Brief summary:

Parkinson's disease (PD) is a neurodegenerative disorder involving a part of the brain that is responsible for motor control, which not only results in changes or disruptions in movement, but also cognitive dysfunctions. Given that the decline of muscle control such as tremors, with difficulty walking or the ability to switch tasks once in movement, greatly affects the quality of daily life. Action regulation is a critical executive function (cognitive control over behavior), which includes actions such as suppressing activity when selecting between options, making decisions about stopping unwanted or inappropriate actions, and switching to new actions in response to environmental changes. Parkinson's disease (PD) has been shown to disrupt action inhibition which can be considered a measure to the progression of PD.

The purpose of this research study is to better understand the mechanism of action regulations in PD patients and how action regulations in PD can be improved using dopaminergic treatment, which is a drug that either releases or involves dopamine, which is a neurotransmitter involved in sending signals to nerve cells.

You are asked to participate in this research study because you are receiving a dopaminergic medication for treatment of your Parkinson's disease. There is currently no theory that integrates the mechanisms of action regulation into a unified framework, which this study aims to address. The researchers hope to learn more about the mechanisms of action regulation in PD patients and to help decrease action regulation disruptions in PD patients. This study will help characterize the motor behavior of PD patients.

Conditions

Parkinson Disease

Study ID

NCT06489483

Start date

Apr 24, 2024

Status verified date

Dec, 2025

Completion date

Nov, 2027

Anticipated

Primary completion date

Nov, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Accepted

For Parkinson's Disease Patients:

Inclusion Criteria:

  • Diagnosis of Parkinson's Disease by a movement disorder neurologist
  • Levodopa responsive with clearly defined "on" periods, with at least 30% improvement in UPDRS III scores on vs off
  • Willingness and ability to complete the behavioral experiments for up 3.5 hours
  • No vision or hearing problems that impair ability to participate with the proposed tasks as assessed by the study investigators

Exclusion Criteria:

  • Patients with history of secondary Parkinsonism, stroke, or progressive central nervous system disease other than Parkinson's Disease
  • Patients with a disease or condition that prevents understanding or communication of informed consent, study demands, and testing protocol including cognitive decline, diagnosed forms of dementia, significant memory impairment (MoCA<23), or hearing loss that prevents adequate communication with researcher

For Healthy subjects:

Inclusion Criteria:

  • No history any diagnosed neurological disease(s), including movement disorders or cognitive decline
  • No vision or hearing problems that impair ability to participate with the proposed tasks as assessed by the study investigators

Study Design

Enrollment

50 participants

Anticipated

Allocation

Non randomized

Intervention Model

Single group

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Parkinson's Disease Patients

Patients that have been diagnosed with Parkinson's Disease and are responsive to levodopa medication. Patients will complete a behavioral task.

active comparator: Healthy Controls

Men and women between the ages of 18-80. Spouse of PD patient who participates in this study with no history of any diagnosed neurological disease(s), including movement disorders or cognitive decline. No vision or hearing problems that impair ability to participate with the proposed tasks as assessed by the study investigators.

Interventions

Action Regulation Movement Task

A joystick is utilized to trace the movement of a visual stimulus on a computer screen. In stop signal task, the subjects are required to move a reference dot to reach to a target dot by controlling a joystick and stop their movements when the target turns red. During the switch task, subjects will be required to switch their joystick movement trajectory when the target location is switched to one of the other target locations.

Primary outcome measure

  • Stop-Signal Task [ Time Frame: Baseline ]
  • Switch Task [ Time Frame: Baseline ]

Central Contacts and Locations

Central contacts

Nader Pouratian, MD, Phd

(214) 645-5465nader.pouratian@utsouthwestern.edu

Sahil Chilukuri, BS

(214) 645-5465sahil.chilukuri@utsouthwestern.edu

Locations

University of Texas Southwestern Medical Center

Recruiting

Dallas, Texas, United States, 75390

Contacts

Sahil Chilukuri

sahil.chilukuri@utsouthwestern.edu

Nader Pouratian

nader.pouratian@utsouthwestern.edu

More Information

Sponsor

University of Texas Southwestern Medical Center

Last update posted

Dec 12, 2025

Last verified

Dec, 2025

Keywords

  • Levodopa medication
  • motor cortex
  • basal ganglia

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Texas Southwestern Medical Center on 2025-12-12.